Azimuth instrument.



A. F. H. WEULE.

AZIMUTH INSTRUMENT. l APPLICATION FILED HAILBO, 1910.

Patented Dec. 6, 1910.

2 SHEETS-SHEET 1:.

A. I'. H. WEULE.

AZIMUTH INSTRUMENT.

APPLIUATION FILED MAE. ao, 1910.

2 BHHETB-BHEET 2.

WITNESSES.' IN VEN TOR j rToRNEv.

Patented Dec.6,1910.

- the magnetic latitude causes an ever-varying `siderable as'to render the compass almost nnrrun sragns PATENT onnrcn.

ARTHUR F. H. WEULE, OF SAN FRANCISCO, CALIFORNIA.

AZIIVIUTH INSTRUMENT.

To all whom tt may concern:

Beit known that I, ARTHUR F. H. VnULn, citizen of the United States, residing in the city and county of San Francisco and State of California, have invented new and useful Improvements in Azimuth Instruments, of which the following is a specification.

This invention relates to azimuth instruments.

As is known, great ditliculty is sometimes connected with the use of mariners compasses, arising from disturbing influences of the magnetism of the ship. 'Ihe difficulty is a particularly felt in iron vessels where the deviation of the needle is frequently so conuseless. This difficulty is particularly felt where the ships course runs in such a direction that the latitude changes considerably, as from North American ports to Australia. The magnetism of the vessel changing with deviation of the needle. This deviation of the needle may be either east or west of the true magnetic north and on almost all ships varies several degrees. It is most necessary for the navigator to determine the deviation at different times,` and for this purpose several instruments have been constructed. None of these instruments I consider' very practical, and know of none in which a direct reading of the deviation can be taken. lVith this in view', I have constructed an instrument of which the following is a coinplete description, in which,

`Figure 1 is a perspective view of the instrument. Fig. 2 is a vertical, approximately central, partial section in a plane radial approximately to the segment, C, and parallel with the vertical wire, 4. Fig. 3 is a plan View of a compass showing the instrument in position.

Referring to Fig. 1, the instrument consists of a horizontal main frame portion A, having the two graduated segmental end portions B and C. At the center of this frame is pivoted at 9, a vertically disposed foldable frame 3 carrying the sight wire 4. On the underside of the end C, and pivoted centrally f the main frame, is a supplementary horizontal frame 5 having a vertical segmental ange 6. On the upper edge of flange 6 is pivoted a reflecting mirror 7, sight frame 8, and sighting mask 8. The supplemental frame 5 is also provided with Specification of Letters Patent. Application inea March 3o,

' the correct position; in this case 18.

Patented Dec. 6, 1910.

1910. serial No. 552,343.

a clamp screw 9, for locking it to the segment C, and has a supporting leg 10. Segment B also has two legs 12 for supporting the azimuth instrument on the compass glass D. Pivoted below the frame 5 is the pointer frame 11, carrying the magnifier 11 and cross hair 18, and screw clamp 13 for locking the pointer frame 11 to segment B. The frames 5 and 11 are held in place by the center pin 14, and may swing independently in any direction on this pin. The pin is provided with a center point adapted to engage a center hole 1G in the compass glass D. The two segmental portions B, C are graduated, beginning at the center with 0 to 30 or 40 on each side. The instrument may also be provided with level glasses, as at 24, so that the horizontal position of the instrument can be determined.

Referring to Fig. 3 of the drawings, the dotted line 10 represents the true north and south line, or a line of shade thrown by the sun when at its meridian. To determine the correctness of a compass it is necessary for the navigator to know the exact variation when at a certain latitude and longitude. Charts are provided giving the variations at dierent longitudes and latitudes. For example, at San Francisco the variation between true north and magnetic north is approximately 18, and at different points along the North Pacific coast and Alaska the variation runs over 30. These variations are, as before stated, found on the charts provided for that purpose.

In operation the navigator knowing the variation, say in San Francisco Bay, to be 18 (actually about 17 30 E.) will move the pointer frame 11 until the cross hair 18 on the magnifier registers with 18 on the segment B. The vertical frame 3 is provided with a sighting piece 19 through which the operator may sight on line Q0 to sct the cross hair 1S on the pointer :traine in The screw clamp 13 is then tightened so that the pointer frame is locked at the position indicating 18. The instrument is then placed on the compass, care being taken that the center point engages with the center hole of the compass glass. The instrument is then swung around into such a position that the cross hair stands in a line directly above 0 south, as shown in Fig. 3. At this particular position the instrument has been set for apparent noon at that place. Now if the compass is correct and the stili is at its meridian, the Wire 4C in frame i3 will throw a line of shade directly across 0O on segment C. lf the compass is not correct, the shadow of wire et will fall ,either to one side or the other of 0, indicating that the compass has so many degrees easterly or westerlydeviation, whichever the case may be. The vertical segmental portion otithe frame 5 may be enameledwhite or any other suitable color lt0`show the `shade line thrown by the wire l on frame 3. It can thus be seen that a direct reading is made indicating the deviation not the compass, something not accomplished by any instrument heretofore.

Sometimes :it is desirable to .malte the compass correction at night Iby the position of some `known fixed star, as the North Star. In this case itis necessary to sight through the slot yin the sighting frame 8, bringing the .cross wire 4f in line `with the star, thus givingithe-true north and south. rEhe sight` ing frame and reflecting mirror being pivoted may be turned at any yangle mostsuitable for fthe operator.

The instrument is placed, as previously described, with the cross hair 18 on vthe pointer frame directly above south on Athe compass. It is then `necessary to swing the supplementary frame around on its pivot until ailine can be taken through the sighting frameand cross wire l to the star. The vertical portion is marked in thecenter, as shown at 22. If this line, being in line with the sightingframe,.registers Oo on `the graduated segment C, the compass is correct. lf the line-22 registers east or west of 0O itindicatesthe compassto have somany degrees deviation east or west.

It .will be understood that the instrument may 'be used -fin different ways, as with `azimuth Compasses and dials. The compass being mounted on gimbals, it can be -seen that fthe swinging or swaying -of the ship will :not aitect the instrument.

The slotted sight frame S-and mirror may also be used-on cloudy days andif the sun is only partially obscured by clouds or haze so'thatit is too dull to cast a proper shadow onthe 4whitened wall of the flange G, and yet isitoo strong when reflected in the mirror for the operators eyes, the mask 8 may be turned up so that the operator can peep through the colored glass ofthe mask and the slot'andsighting frame 8 and make his proper adjustments.

Having thus ldescribed my invention, what lclaimnnd'desireto secure by Letters-Patent, is:

l. An azimuth instrument consisting of a frame `with segmental graduated ends .in a horizontal plane, said sections having a common center, `a vertically disposed sight t-urnable on horizontal pivots and carrying said sight wire.

2. An azimuth instrument consisting of a frame with segmental graduated ends in a horizontal plane, said sections having a common center, a vertically disposed sight wire arranged at said center in a plane at right angles to the plane of said end segments, a supporting frame for the sightwire, a movable member pivoted .concentrically with an ,end segment and having a vertical flange concentric `with said end segment.

3. An azimuth instrument consisting of a frame with segmental graduated vends in a horizontal plane, said sections having a common center, a vertically arranged sight wire disposed at `said center in a plane at right angles to the plane of said end segments, means for supporting said sightwire, a movable member pivot-ed concentrically with the end segments and having a radial cross-hair arranged in a plane coincident with said sight wire, a movable member pivoted concentrically with the end segments and having a vertical flange-a mirror carried by the fiauge and a vertically slotted sight member on the mirror with a slot in the Vplane ofsaid -sight wire.

4. An azimuth instrument consisting offa frame with segmental graduated Aends in a horizontal plane, said sections having a common center, a vertically arranged sight wire disposed at said center in a plane :at right angles tothe plane of said end segments, means -for support-ing said sightwire, a movable member pivoted concentrically with the end segments and having a radial cross-hair arranged in a plane coincident with said sight wire, a second:movablesmember pivotedconcentrically with said end segments and .having a lflange,a mirror carried by the flange, a vertically slotted sight niember on the mirror with a slot in the plane of said sight wire, and a mask for said slotted sight member.

5. An azimuth instrument consisting of a frame having two end segments having a common center and each segment graduated from its middle to each side, a sight wire disposed at said center in a plane at right angles to the plane of t-he segments, means for supporting said sight wire, a iframe adapted to swing under -one of said segments and `having means Yfor :locking it thereto and carrying a 'radial ecross-hair which is arranged in the same plane as .the sight wire, and a flange coneentricwith the other end segment and projecting `there- "lol above and having a graduation mark alinable with the graduations on said end segment.

6. An azimuth instrument consisting of a frame having two end segments with a common center and each segment graduated from its middle to each side, a sight wire disposed at said center in a plane at right angles tothe plane of the segments, means for supporting said sight wire, a frame adapted to swing under one of' said segments and having means for locking it thereto and carrying a radial cross-hair which is arranged in the same plane as the sight Wire, a flange concentric with the other end segment and projecting thereabove and having a graduation mark alinable with the graduations on said end segment, and means whereby said flange is mounted to swing in an arc concentric with its end segment.

7. An azimuth instrument consisting of a frame having two end segments with a common center, each segment being graduated from its middle to each side, a sight wire disposed at said center in a plane at right angles to the plane of the segments, means for supporting said' sight wire, a frame adapted to swing under one of said segments and having means for locking it thereto and carrying a radial cross-hair which is arranged in the same plane as the sight wire, a flange concentric with the other end segment and projecting thereabove and having a graduation mark alinable with the graduations on said end frame, means whereby said flange is mounted to swing in an arc concentric with its end segment, and a mirror and slotted sight member carried by the flange and adapted to co-act with said sight wire when the instrument is used.

S. An azimuth instrument consisting of a frame ha ving two end segments with a common center, each segment being graduated from its middle to each side, a sight wire disposed at said center in a plane at rivht angles to the plane of the segments, an a frame adapted to swing under one of said segments and having means for locking it thereto and carrying a radial cross-hair which is arranged in a plane coincident with the sight wire, and a slotted frame pivoted on horizontal pivots at a point proximate to the radial center of the two segments, and carrying said sight wire.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

ARTHUR F. H. VEULE.

Vitnesses EMIL GINGG, M. V. COLLINS. 

